1. Field of the Invention
The present invention is related to the field of packet networks, and more specifically to devices, softwares and methods for enabling devices to operate in networks of diverse protocols.
2. Description of the Related Art
Packet networks are increasingly used for communications. Such communications include data, and also voice for packet telephony, and so on.
Each network transmits information in packets, according to a certain protocol. Packet telephony, for example, may take place under a Voice over Internet Protocol (VoIP).
The protocol is so important that networks, devices, and even messages are often labeled by their protocol. One well established such protocol is the H.323 of the IETF (Internet Engineering Task Force). Networks that operate under this protocol are therefore often called H.323 networks, and so on.
A problem arises when components are developed that operate under a different protocol. One such protocol that is gaining increasing acceptance is the Session Initiation Protocol (SIP). Devices that use the SIP protocol are called SIP devices.
Components of a newer protocol are typically not usable in networks of an older protocol. This is a problem when a large (“legacy”) infrastructure has been installed according to the older protocol. For example, SIP devices are not usable with H.323 networks, and H.323 devices are not usable with SIP networks.
Referring to FIG. 1, one facet of the problem is described. A H.323 packet network 110 has a CSR Gatekeeper 120, a directory gatekeeper 130, and a device with a memory 140 that has configured routes stored therein.
A gatekeeper is the “switch” of the network, providing several basic services to all endpoints in its zone. Services include address translation (alias name/number-to-network address), endpoint admission control (based on bandwidth availability, concurrent call limitations, or registration privileges), bandwidth management, and zone management (the routing of calls originating or terminating in the gatekeeper zone—including multiple path re-route). Additional gatekeepers (not shown) may or may not be provided in a cluster according to the invention.
A routing application 150 runs on CSR Gatekeeper 120. Network 110 may also have one or more dynamic protocol devices 162, 164. These run dynamic protocols, such as Telephony Routing over IP (TRIP), or H.323 Annex G Protocols. Network 110 is accessed via a H.323 gatekeeper 170 as follows. A first H.323 endpoint 180 accesses H.323 gatekeeper 170, and then communicates address information to a second H.323 endpoint 190. These and other devices of network 110 may be connected to the PSTN (Public Switched Telephone Network), to an ISDN (Integrated Services Data Network), etc.
With a network such as network 110 customers may implement arbitrary routing applications, using configured gatekeepers, networks of directory gatekeepers, carrier-sensitive routing, other means, or combinations of the above.
The problem with H.323 network 110 is that it can not be accessed by a SIP device.
Referring to FIG. 2, another facet of the problem is described. A SIP packet network 210 has a CSR proxy 220, a proxy 230, and a proxy 240 that has configured routes stored therein. A routing application 250 runs on CSR proxy 220. Network 210 may also have one or more dynamic protocol devices 262, 264, that run on suitable dynamic protocols.
Network 210 is accessed via a SIP gatekeeper 270 as follows. A first SIP User Agent (UA) 280 accesses SIP gatekeeper 270, and then communicates address information to a second SIP UA 290. A SIP UA may be SIP IP telephone, or POTS/SIP IP media gateway. (“POTS” stands for Plain Old Telephone System.)
Other terminology for SIP is found in a website which, at the time this document is initially filed with the U.S. Patent Office, has a URL of <http://www.cs.columbia.ed/˜hgs/sip>.
The problem with SIP network 210 is that it can not be accessed by a H.323 endpoint device.